Sanfilippo type B: developing a new treatment for this rare and devastating disease

Sanfilippo type B is a rare illness that starts to cause problems when children are just two, three or four years old. At first, children may simply seem naughty or hyperactive. Sadly though, they go on to experience a gradual but relentless deterioration in their mental and physical abilities, with few living beyond their teenage years. There is no cure. Dr Brian Bigger, of the University of Manchester is developing a new treatment in the hope of improving the lives of both children and their families.

How are children’s lives affected now?

Children with Sanfilippo type B usually develop normally for the first year or two of their lives. Sadly, though, in the years that follow, the children’s condition deteriorates in a devastating way.

“Children with Sanfilippo type B develop severe behavioural problems,” explains Dr Bigger. “They lose their sense of danger, and become hyperactive and inattentive. They lose their language skills and have severe learning disabilities. Sleep patterns also tend to be disrupted.”

Over the course of several years, the children’s behavioural problems are slowly replaced by physical disabilities. These get worse over time, with children needing to use a wheelchair and becoming entirely dependent on their parents and carers.

“Parents are vital in children’s lives, with their love and care being extremely important,” explains Dr Bigger. “But it can be hard for parents to deal with things like the lack of sleep, their child’s behavioural problems and difficulties in communicating. New treatments are desperately needed.”

How could this research help?

“We are in the laboratory stages of developing a new treatment for Sanfilippo type B, which is also called mucopolysaccharidosis IIIB,” explains Dr Bigger.

Children with this disease have faults – or mutations – in a particular gene. The new treatment aims to overcome these faults by delivering a healthy copy of the gene to the body. This type of treatment is called gene therapy.

For the children the new treatment will involve having a bone marrow transplant. The plan is to take cells from the children’s own bone marrow, modify those cells using gene therapy, and transplant them back into the children’s body.

“Sanfilippo brings with it such a wide range of devastating problems that any improvement in the children’s condition would be beneficial,” says Dr Bigger. “But we are hoping the new treatment will one day make a significant difference to the lives of children and their families.”